Even if the price of bitcoin comes down it is still possible for you not to even invest because what if the price didn't reduce to what you already have in mind it means you won't be be convinced to invest bitcoin,  because as you want the price of bitcoin to come down there is a certain amount which you want to fall to. From experience and from other people I have come across waiting for the price of bitcoin to fall first before buying, in most cases people with thos mindset don't end up buying bitcoin because even if thr price of bitcoin falls they are not okay with it and they keep on waiting it will fall to the price which they have in mind.

There is no perfect time to buy bitcoin to invest, you can buy bitcoin at anytime and still make profit from it as far as you have it in mind to go for a longterm investment, it is not an investment to wait to buy when the price falls, if unfortunately the price falls then it is also an opportunity to buy but it is not necessary to wait for the price you have in mind to buy bitcoin.